I tried to mail an envelope weighing 1.1 ounces, measuring 9.5" x 5.5" x 0.1" thick, containing 1 CD and 1 sheet of paper with an $0.86 stamp ($0.66 for the weight, and $0.20 for the non-machinable surcharge due to the rigid object). The mail was returned to me for "insufficient postage". I hand-carried it to the post office that returned it (at 5900 Barclay Dr., Alexandria, VA) and asked the employee why it was returned. She said that since it contains a CD, it needs to ship at parcel rate. I found this puzzling, since Netflix and many other companies mail CDs at First Class letter rates. I told her that $0.86 is the postage price given to me by the automated postal center machine in the lobby for this particular envelope, given its size, weight, and rigidity. She said, "Oh, that machine doesn't know about mailing a CD." When she could see that I didn't believe her, she turned to another employee (who had been listening to the whole conversation) and asked, "How much to mail a CD?". That other employee also said, "It has to be mailed at parcel rate." Are all these USPS employees correct?